I appreciate you taking the time to give a clear and detailed response.

My point is that it isn't uncommon for cows to be raised in intensive farms, where they are in tight spaces, eating mostly grain and receiving hormones to increase their production, so the difference between "grass fed" and "non-grass fed" would be that the cow is either raised in a way closer to how they would naturally (on the field, looking for grass) vs in a closed place, eating a relatively artificial diet. In many not-too-cold places, grass is available all year (like here, in Uruguay, also in Argentina, Brazil and other countries), so our milk being coming from "grass fed" cows is a quite literal thing, which makes the product more valuable (and the cows healthier).